Cam decision....gt40 heads

[TX93Cobra]

i have ported with 3 angle valve job on my gt40 original heads and right now im running with an e303 cam but im thinking a single pattern cam is like what ive read around outdated. and i was going to go with a exhaust biased duration cam like an anderson n-21, or maybe a crower cam.. any ideas?? im looking for a tad more power down low than the e303 and a better idle but still lopey...

 

[93Cobra#2771]

Honestly, that's a lot of trouble to go through for not much of a change in power. It's hard to have the lopey idle and power down low.

I've considered pulling my steeda #18 cam and going to a more mild and EEC friendly custom grind. I'd lose probably 5-10 peak hp, bit pick up a ton of bottom end torque and drivability. The smooth and flat torque curve offered by such a cam, especially under 3000 rpm, would be worth it for me.

Then again, I'm not 25 years old any more.

 

[TX93Cobra]

well i figured if i still went with a 110 lsa cam the idle would be still rough and lopey. which i guess that throws drivability out the window but i think a cam with maybe a 218/224 duration or 219/229 would be better, but i dont know how much i would see in results....

 

[93Cobra#2771]

My cam specs out at 220/226, 512/512, with I think a 114 lsa. You will gain very little by changing from the ecam, and you will gain some worse drivability in my opinion. Now I won't lie to you, it sounds awesome and absolutely pounds the ground. Without tailpipes it sounds like a race car. But drivability stinks. I tamed a lot if it with a tweecer rt, but really need to play with the tune some more.

A friend of mine with ported stock heads, lightly milled to bump compression, and same cam as me dynoed at 274 horsepower. And would have given anything to put a milder cam in before he sold the car.

 

[TX93Cobra]

yea.... maybe i wont... idk.. still just wanted to test with some things..Thanks for the advice man. i just figured with a full port and valve job and ported intake, id put down more than 264, and definately thought id put down more than 304 ftlbs. so i thot there might be a little power sitn on the table... and it is dyno tuned...

 

[carrew]

Ed curtis can wittle you a custom grind matched for your combo. http://www.flowtechinduction.com/

He did one for my old GT40P, ported cobra intake, stock block combo and it was running 300rwhp.

 

[buddha93]

Just for comparison sakes, not really apples to apples, but my buddies car put down 340rwtq with Ricks' N-41 cam. Here's the details:

TFS combo w/ Anderson n-41 - Corral Image Hosting

 

[TX93Cobra]

yea i was lookn at andersons cam n-21 since i have 1.7rr. look like great cams, but ya i wont have the alum heads so idk.

 

[buddha93]

I wouldn't worry about the aluminum vs. iron, but as to how much you heads are ported.

 

[04MystiCobra]

My cam specs out at 220/226, 512/512, with I think a 114 lsa. You will gain very little by changing from the ecam, and you will gain some worse drivability in my opinion. Now I won't lie to you, it sounds awesome and absolutely pounds the ground. Without tailpipes it sounds like a race car. But drivability stinks. I tamed a lot if it with a tweecer rt, but really need to play with the tune some more.

A friend of mine with ported stock heads, lightly milled to bump compression, and same cam as me dynoed at 274 horsepower. And would have given anything to put a milder cam in before he sold the car.

Funny. I ran the same cam and the Tweecer RT as well. Did you try a different maf? I used my 04s sensor and that seemed to help alot after refining of the tune. I loved the sound but like you low rpm manners werent were sometimes a pain. I didnt notice the lack of low end tq though since I was running alot of boost. Before that I ran the B303 (back when that was a cool cam lol) and the Steeda 18 was tons better in the low end. I'd have to agree though. Changing cams w/ the GT40 type heads will only give you slight power gains but the impact on drivability can be huge. :beer:

 

[93Cobra#2771]

Funny. I ran the same cam and the Tweecer RT as well. Did you try a different maf?

ProM 80 with an AFM power pipe. I put the ProM calibration table in on the tweecer.

I used my 04s sensor and that seemed to help alot after refining of the tune. I loved the sound but like you low rpm manners werent were sometimes a pain.

I did all my tweecing in 2002 or so, so no 04 sensor to play with. Probably a nice option. I actually made it mostly livable with the tweecer once I datalogged enough to figure out what was going on.

I didnt notice the lack of low end tq though since I was running alot of boost. Before that I ran the B303 (back when that was a cool cam lol) and the Steeda 18 was tons better in the low end. I'd have to agree though. Changing cams w/ the GT40 type heads will only give you slight power gains but the impact on drivability can be huge. :beer:

I imagine boost did help low end. I'm probably exaggerating on the low end loss. The cam is a little more peaky than I like, meaning it doesn't really start hitting hard till about 3500 rpm, so it feels a little weak down low in comparison. I've actually considered swapping back to the stock cam, if you can believe that. But reality is I'll go with a custom grind from buddy rawls on my car. Already have it specced out, just a matter of getting it done. I want some street bruising low end torque. :-D

 

[TX93Cobra]

I wouldn't worry about the aluminum vs. iron, but as to how much you heads are ported.

thats the unfortunate thing when i got the ported and everything i didnt end up getting them benchflowed. i wanted to but i ran out of funds haha. so i guess that knocks out getting a custom grind?? dont they need that info for one?

 

[TEAL VNM]

Hey Nick

I like my N-41 but not great drivebility down low. Sounds awesome at idle tho.

 

[TX93Cobra]

Hey Nick

I like my N-41 but not great drivebility down low. Sounds awesome at idle tho.

yea it does, but arent you running 1.7rr? it says on afm site that the n-41 is best used with 1.6rr and the n-21 with 1.7 if i remember...

 

[93Cobra#2771]

thats the unfortunate thing when i got the ported and everything i didnt end up getting them benchflowed. i wanted to but i ran out of funds haha. so i guess that knocks out getting a custom grind?? dont they need that info for one?

They don't HAVE to have flow bench numbers to do a custom grind.

 

[TX93Cobra]

They don't HAVE to have flow bench numbers to do a custom grind.

oh okay. wasnt sure or not.

 

[TEAL VNM]

I am running 1.7s with the N-41. AFM reccomends using 1.6s because you can have problems with piston to valve clearance if your pistons are not notched.

 

[TX93Cobra]

I am running 1.7s with the N-41. AFM reccomends using 1.6s because you can have problems with piston to valve clearance if your pistons are not notched.

oh okay i have notched Keith Black pistons. well shoot man ill probably be ordering that cam then. sounds nasty and ran well. have u had it dynoed yet?

 

[buddha93]

I'd still double check it. Nothing worse that smacking valves against pistons.

 

[TEAL VNM]

I have not had her to the dyno yet. Im planning on getting it tuned next month after I get the S-trim on.